Trag'Oul was bar from interning the final events of the Sin War by other watchers and latter guide Rathma and Kalan on continuing their studys on the Balance, but since then we have no idea on his activities.

No clues to what happen to him after the Worldstone shattered or if he's still around to aid Sanctuary and the necromancers in the 20 years.

Actuallyy he is not present in the game events...not as i can remember.It seems that since Uldyssian made changes in the Worldstone, Trag'oul 's influence under the sanctuary has diminished. Perhaps we can learn some more now in the events of D3, but i bet this would be an explored topic of the lore...sadly.By the way, trag'oul is a kind of spirit, not a living being, and therefore cant be dead or something. its like Diablo himself. But i like to think of him more like an ethereal thing.I cant remember if it was mentioned that he is dead though. Probably dont.

Also Traq'oul is mentioned in one of the stand alone diablo books (the one about the city of shadows) when the necro chick was praying to him to cast teeth. The necros also get their magick through his teachings-maybe from him so if he was not still around then necros could not cast.

I don't think they draw power from him, Mendeln/Kalan does things Trag'oul thought were impossible. If they were drawing power from him, he's have a general idea of what could be accomplished and not speechless when someone does something.

Hes the fallen star! I heard one of the characters say they sensed some strange unknown magic about the hole and also undead stuff starts popping up! Kinda lame and predictable if it were tyrael like everyone else is saying.

And no he wasn't speechless about their ability to use it, he was speechless because it was something that even they couldn't do.

We can also gather this information in the respect that the type of magic the Necromancer's use is in line with how a mage/wizard uses magic. It is a discipline through knowledge, a principle in manipulating the forces that are at work in the universe. The difference is that the Necromancers primarily focus on magic that the Vizjerei would simply overlook and have little to no knowledge of.

Hes the fallen star! I heard one of the characters say they sensed some strange unknown magic about the hole and also undead stuff starts popping up! Kinda lame and predictable if it were tyrael like everyone else is saying.

That's just Boxer Brown saying it, he's posted it on multiple threads and even made one of his own It's either Tyrael is a Badguy, OR Tyrael= Diablo

On a semi related note I imagine Trag'Oul looking like a Frost Wyrm from WarCraft III or World of WarCraft. And from Richard Knaak's Characterization He sounds like a Dragon Aspect, probably has the same Powers as a Dragon aspect.